Air separator



Nov. 7, 1933. T. J. STURTEVANT AIR SEPARATOR Filed Nov. 25, 1930 3 Sheets-Sheet 1 IN VEN TOR Z0 TORNEY Nov. 7, 1933. T. J. STURTEVANT 1,933,606

AIR SEPARATOR Filed Nov. 25, 1930 3 Sheets-Sheet 2 Fly. 2

IN VEN TOR Nov. 7, 1933. T. J. STURTEVANT AIR SEPARATOR Filed Nov. 25, 1930 3 Sheets-Sheet 3 l atentecl Nov. 7, 1933 UNITED STATES A matte 1,933,606 AIR SEPARATOR Thomas J. Sturtevant, Weilesley, Mass, assignor to Sturtevant Mill Company, Boston, Mass, a corporation of Massachusetts Application November 25, 1930 Serial No. 498,072

3 Claims. (01. 209-439) The invention to be hereinafter described relat'es to air separators for grading materials.

The invention is embodied in a separator of the type in which the classification is accom- 5 plished by an air current moving upward in a separating chamber and downward in a settling chamber. The air current is induced by a fan and caused to circulate through the chambers, and in its course passes through an inlet open- 0 ing adjacent the lower end of the separating chamber, and through an outlet opening at the upper end of the separating chamber. The materials to be graded are fed through a hopper into the separating chamber, and are received by a rotary distributor which throws the materials out across the rising air current under the influence of centrifugal force. The lighter particles are carried upward by the air current through the outlet opening over into the settling chamber where they gravitate downward and are discharged therefrom, while "the heavier particles or tailings gravitate downward through the rising air current in the separating chamber and are discharged therefrom.

The fan for inducing the circulating air current is located above the outlet opening at the upper end of the separating chamber. For efficient classification, heavier particles should bev prevented from being carried by the air current 'up through the outlet opening. To prevent this, a fan has been employed in the separating cham ber beneath and adjacent to the outlet opening to promote whirl of the current with centrifugal effect which throws the heavier particles out toward the wall of the separating chamber, and materially reduces the liability of their being carried out with the fines. However, such a fan tends to produce suction down through the outlet opening which must be overcome by the fan above said opening, in order properlyto maintain the. air circulation In separating certain grades of material, the fan above the outlet opening should be rotated at high speed, but this requires an objectionable amount of power, in creases the cost of operation, and produces excessive wear on the parts.

A purpose of the present invention, therefore, is to provide a construction whereby the whirl of the air current and centrifugal effect are promoted in the separating chamber beneath-the outlet opening, but without producing downward suction through said opening sufiicient to materially add to the duty of the fan driving means. In carrying theinvention into practical effect, spaced rotary plates or rings are provided between the distributor and the outlet opening, the

construction being such that the materials thrown outwardby the distributor into the path of the whirling rising current in the separating chamher, will be carried up to theperipheries of the rings. The air current will pass on between the rings toward the axis of rotation of said rings, and thence up toward the outlet opening. The rotating rings will develop a whirl of the air between them creating a centrifugal effect which rejects the coarser particles and throws them outward toward the wall of the separating chamber where they gravitate downward through the whirling rising air current. On the other hand the finer particles are carried along with the air current up through the outlet opening and over into the settling chamber.

' The character of the invention will be best understood by reference to the following description of an embodiment thereof shown in the accompanying drawings, wherein:

Fig. 1 is a vertical section through the air separator; v I

Fig. 2 on an enlarged scal is a perspective view of sections of the spaced rings;

Fig. 3 is a horizontal section taken on 3-3 of Fig. 1; s

Fig. 4 is a horizontal section taken on line ll of Fig; 1;

Fig. 5 is a plan of a modified form of rings mounted on the baflie plate; and

Fig. 6 is a perspective view of portions of the baiile plate and rings.

Referring to the drawings, the separator shown therein as one good embodiment of the invention, comprises an outer casing 1 consisting ofa drum 3 having a head 5 at the upper end thereof, and a cone 7 at the lower end thereof termimating in a discharge spout 9. Within and spaced from the outer casing is an inner casing 11 consisting of a drum 13 having a head 15 at the upper end thereof with an outlet opening 17 therein. Projecting down from the drum 13 is a conical shell 19, and beneath and spaced therefrom a conical shell 21 terminating in a discharge spout 23 extending laterally through an opening in the cone '7. The drum 13 of the inner casing is supported by brackets 25 secured to the outer and inner drums.

In the inner casing is the separating chamber 2'7, and between theinner and outer casings is the settling chamber 29. The space between the conical shells l9 and 21 of the inner casing serves as an inlet opening 31 for the passage of air from the settling chamber into the separating chamher. Located at this space is a series of vanes 33 (Figs. 1 and 1) having flanges 35 at the upper ends thereof pivotally connected to a ring 3'7 secured to and projecting outward from the lower edge of the conical shell 19.

These vanes are adjustable to vary the area of the inlet opening, and to accomplish this, the vane flanges carry and are pivotally connected to a ring 39. A rod 11 has one end pivotally connected to said ring, and extends through a sleeve bracket 43 secured to the outer casing drum. A hand wheel 15 is mounted on the bracket and has a hub threaded to the rod and confined against movement axially thereof. Rotation of the'hand wheel will adjust the rod longitudinally relatively to the bracket, and thereby impart rotative adjustment to the ring 39, which will rock the vanes to vary the spacing between them. These vanes and the means for adjusting them may be similar to the construction disclosed in Letters Patent No. 1,788,361, granted to me January 6,

' 1 and 4) resting upon said head and provided channel mounted on the channel 61.

with radial bars or handles 49 which extend through guides 51on tllbl'itfikBtS 25, and guides 53 on the outer casing drum. The handles are accessible exteriorly of said drum for adjusting the plates radially inward or outward to vary the area of the outlet opening. This valve may be similar to that disclosed in Letters Patent No. 1,615,558, granted to me January 25, 1927.

The materials to be graded are conducted into the separating chamber through an upper hopper 55 and through a conical hopper 57 secured to and depending from the outer casing head, with a neck 59 extending down through the'outlet opening in the separating chamber head.

Mounted on the outer casing head are channels 61 supporting a housing 63 having bearings in the lower and upper endsthereof in which a shaft 65 is journalled, and extends downward through the hopper 59 into the separating chamber. A

bevel gear 6'? fast on said shaft meshes with a bevel pinion 69 fast on a horizontal shaft 71 journalled in a bearing carried by the housing 63 and in a bearing 73 carried by a transverse At the outer end of the shaft 71 is a pulley 7'7 which may be driven from any suitable source of power.

Mounted on the vertical shaft beneath the hopper necl: 59 is a rotary distributor '79 having a hub 81 with a plate 83 bolted thereto. Projecting up from said hub are posts 85, and secured thereon is the lower flange 87 of a sleeve hub 89,

at the top of which is a dished flange 91. Secured to the latter are upwardly inclined arms 93 carrying the fan blades 95 located above the outlet opening and in a chamber 9''! between the outer and inner casing heads. This fan serves to develop the air current which whirls and circulates through the fan chamber 9'7, the settling chamber 29, the inlet opening 31, the separating chamber 2'1, and the outlet opening 1'7.

The materials to be graded are fed through the hoppers 55 and 5'? to the distributor 79, and are thrown outwardly thereby under the influence of centrifugal force toward the wall of the separating chamber. They meet the upward whirling air current, the lighter particles being carried through the outlet opening over into the settling chamber, while the heavier particles or tailings gravitate downward through the rising air current in the separating chamber, the fines and tailings being discharged respectively through the spouts 9 and 23.

At stated, a purpose of the present invention is to provide means between the distributor and the outlet opening for promoting whirl of the air current to prevent larger particles from being carried with the fines up through the outlet opening'. This means, in the present instance comprises a series of plates or rings 99 (Figs. 1 and. 2) in spaced superposed relation and mounted on a bafile plate 101 bolted to thehub flange 87, said baffle plate being considerably larger in diameter than the distributor plate 83, and formed of sections 102 bolted together. The rings are formed of sections bolted together, and they are spaced by collars or spools 103, and the assembly of rings and spacing spools is secured to the outer margin of the baflie plate 101 by bolts 105. The ring structure is located beneath the cover or head 15 of the inner casing surrounding the outlet opening. The baflie plate 101 and the rings are solid and without openings therein.

The construction is such that the whirling rising air current in the separating chamber will pass inthe direction indicated by the arrows in Fig. 1, inwardly through the passages between the rings toward their axis of rotation, and upward through the outlet opening. The fines will be carried through said passages, but the whirl of the air and centrifugal eifect promoted by the ring structure rotating at high speed will reject the coarser particles and prevent them from entering the passages between the rings. They will be thrown outward against the wall of the separating chamber and gravitate downward through the air current and be discharged therefrom.

This separator may classify materials of varying character, and separate fines of varying sizes. By adjusting the vanesat the inlet opening and the valve at the outlet opening, or either of them, the volume and velocity of the air current passing therethrough may be regulated with resultant varying of the classifying eflect.

Referring now to Figs. 5 and 6, the construction shown therein comprises a polygonal baflie plate 107 formed of sections 109 bolted together.

Rings 111 are mounted on the'plate and comprise bars 112 spaced by sleeves or spools 113 and secured in assembled relation by bolts 115' which pass through the spacing spools and registering holes in the bars and baffle plate.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations may be made therefrom without departing from the spirit and scope of the'appended claims.

What is claimed is:

1. An air separator'for classifyingimaterials comprising a covered casing having a centralized top outlet opening and a bottom inlet opening, means for creating a whirling air current within the casing flowing upward through said openings, a rotary distributor intermediate said inlet and outlet openings, a solid bailie plate above the distributor of greater diameter than said outlet opening and formed of sections connected together at their meeting edges, a spaced series of bolts rising from the upper face of said bafiie around its outer'margin, a vertical series of peripheral rings each of substantially the same width and each formed of connected sections mounted on said bolts in superposed relation, said rings being spaced from the battle plate and-from was ach other by spools of substantial diameter relative to the width of said ring sections, said bolts being passed through the baflle, the superposed ring sections and the spools clamping said ring structure to said margin of the baflie plate, and

the entire ring structure lying outside of said outlet opening and closely below the cover surrounding said opening.

2. An air separator according to claim 1 in which the sectional baiiie plate is polygonal in plan and each ring section consists of a narrow plate", the plates of which each ring is formed being connected end to end and angularly related THOMAS J STURTEVANT 

